Was really surprised upon first application because it sort of stung...?Something on the packaging noted that it's caused by one of the ingredients so it's natural. The thick paste leaves a white cast so I recommend applying this at night or in the morning if you know you're applying a tone-up sunscreen or makeup after. This didn't help my cystic acne (which I really wanted it to) BUT it does fade redness. I have some serious redness around my nose and upper lip area from acne, winter dryness, and constantly blowing my nose so I tried this on the whim and to my surprise, it worked! The effect isn't immediate of course, but after about a week or two I realized the redness was less apparent! I'm like, ok... TIAM, I see you... I don't know about repurchasing this considering the increased frequency of niacinamide appearing in skincare these days, but for concentrated treatment this is pretty darn good. I hope to see the redness completely gone when I empty this tube!